Fabric waterproofing process

ABSTRACT

Fibrous cellulosic and proteinaceous materials are waterproofed by immersing them in a solution of an Alpha -pyrone in an inert organic solvent.

United States Patent 1 Rothman et al.

[ 1 Aug. 12, 1975 FABRIC WATERPROOFING PROCESS 22 Filed: May 28,1974

21 Appl. No.: 473,476

[52] US. Cl 8/120; 8/128 R; 8/142;

8/127.5; 8/131; 117/1355; 117/1395 F [51] Int. Cl? D06M 13/20 [58] Field of Search 8/120, 128 R, 142, 127.5,

[56] References Cited UNITED STATES PATENTS 3,567,748 2/1971 Rothman 260/4109 Primary ExaminerM0rton Foelak Attorney, Agent, or FirmM. Howard Silverstein; Max D. Hensley; William E. Scott 5 7] ABSTRACT Fibrous cellulosic and proteinaceous materials are waterproofed by immersing them in a solution of an a-pyrone in an inert organic solvent.

5 Claims, No Drawings FABRIC WATERPROOFING PROCESS The invention relates to a process for waterproofing fibrous cellulosic materials such as cotton and paper and fibrous proteinaceous materials such as wool, leather and fur. More specifically, it relates to the use of a specific a-pyrone to acylate these materials and render them waterproof.

The advantage of this invention over known prior art is that unlike the fat-liquoring materials and processes now in use, the waterproofing agent is chemically bound to the material being treated. This is in contrast to fat-liquoring, which merely impregnates the substrate material, that is, adds the fat-liquor on to rather than chemically binding it to the substrate. In the present invention, the a-pyrone is not removed by dry cleaning and, in fact, it may be applied during the standard dry cleaning process. Another especially important advantage of the present invention is that no acid catalyst is required. This is a very beneficial feature because it avoids fabric weakening that often accompanies acid action on the fabric. Also important is the fact that no heat treatment, other than that used to warm or reflux dry cleaning fluid, is needed.

Therefore, it is an object of this invention to provide a novel method for waterproofing fibrous cellulosic and fibrous proteinaceous materials.

It is a further object of this invention to provide a method of waterproofing such materials as have been heretofore named in which the waterproofing agent is chemically bound to the substrate material.

It is a still further object of this invention to provide a method of waterproofing fibrous cellulosic and fibrous proteinaceous materials without subjecting the materials to the fabric weakening action of an acid catalyst.

It is still another object of this invention to provide a method of waterproofing the above-named substrates so that subsequent dry cleaning of the substrate does not affect its waterproofing properties.

It is yet another object of this invention to provide a method of waterproofing fibrous cellulosic and fibrous proteinaceous materials that can be applied during a standard dry cleaning operation.

It is yet a further object of this invention to provide a method of waterproofing fibrous cellulosic and flbrous proteinaceous materials that does not destroy the fibrous nature of these substrates.

In general, the above objects are accomplished by a process wherein fibrous cellulosic materials such as cotton and paper and fibrous proteinaceous materials such as wool, leather and fur are immersed in a solvent such as carbon tetrachloride or dichloroethylene or other inert solvent commonly used in the dry cleaning industry in which is dissolved an a-pyrone of the following structure:

where R is methyl, ethyl or propyl, and R and R are chain alkyl groups having from 12 to 17 carbon atoms and may be derived from saponified vegetable oils or saponified animal oils, or from both of them. Another source of mixed long chain fatty acids from which the desired C to C alkyl groups may be derived is commercial cold-pressed stearic acid. In addition, the process may be carried out in a separate waterproofing operation or as a combination dry-cleaning and waterproofing operation.

The a-pyrones usable in the practice of this invention are made by the following process which is also found as Example 1 in US. Pat. No. 3,567,748:

Isopropenyl stearate 8.03 grams (0.0247 mole), diethylmalonate (B.P. 193 C.), 10.0 ml., and p-toluenesulfonic acid monohydrate (80 mg.) were heated to reflux (pot temperature 185 C.). Soon after reflux acetone liberation was evident, and acetone vapors escaped the short condenser and were trapped in an auxiliary condensing system. The acetone collected and converted to the 2,4-dinitrophenylhydrazone corresponded to 130 mg. of acetone. The refluxing was stopped after 1.5 hours. The orange brown mixture on cooling deposited crystals. Recrystallization from pentane gave the product having double melting point at C. and C. The infrared spectrum of the product in carbon disulfide solution showed principal bands at 1774, 1737, 1644, and 1109 cm.. No hydroxyl bands were noticed in CS solution, but the ultraviolet spectrum in iso-octane showed a maximum at 298 my, log e 3.48. The product was also-found to have a MW of 648 by mass spectrometer; NMR 8 5.22 (singlet), 4.31 (quartet), 0.89, 1.30, and 2.20 p.p.m.; an empirical formula of C H O and hydrolyzes in strong KOH to methyl heptadecyl ketone.

After further crystallization, the a-pyrone used in the following examples to illustrate this invention melted sharply at 76 C. and had the following formula:

C l-I O O EXAMPLE 1 A cotton test swatch was dried under vacuum over P 0 at about 25 C. to a constant weight of 0.4382 gm., immersed in 25 ml. of CCL, containing 1.5 g. of the a-pyrone, refluxed 4 hours and allowed to stand at about 25 C. for 2 hours. The cotton swatch was removed from the CCl extracted for about 16 hours with CHCI dried at about 25 C. under vacuum for 1 hour and then dried over P 0 at about 25 C. for 4 hours. The swatch was then weighed and tested for waterproofness. The amount of oz-pyrone bonded to the material was equal to approximately 1.0% of the original dry weight of the cotton swatch. As a control a second test swatch was treated in an identical manner, except that no a-pyrone was used. The swatch treated with the a-pyrone exhibited waterproofness, while the control did not.

EXAMPLE 2 Whatman No. 2 filter paper was extracted for about 16 hours with CHCI dried under vacuum at about 25 C., and then dried under vacuum over P for about 2 hours. It was then immersed in 30 ml. of CCl containing 1.5 gm. of the a-pyrone and 'refluxed'for 4 hours. It was then extracted for about 16 hours with CHCl and dried over P 0 under vacuum. A second filter paper was processed in the same manner, except that no a-pyrone was used. The paper treated with a-pyrone did not show any significant weight gain but, upon testing, it did exhibit waterproofness, while the control paper exhibited no waterproofness.

EXAMPLE 3 EXAMPLE 4 A filter paper was treated the same as the cotton swatch in Example 3 and upon testing, it exhibited waterproofness.

We claim:

1. A process for waterproofing fibrous cellulosic and fibrous proteinaceous materials comprising immersing the material to be waterproofed in a solution of an a-pyrone of the formula ti -CU-l i,

in which R is methyl, ethyl or propyl, and R and R are long chain alkyl groups containing from 12 to 17 carbon atoms.

2. The process of claim 1 in which the a-pyrone is 3. The process of claim 2 in which the solution contains about 5.0 to 6.0% of a-pyrone on a weight per volume basis.

4. The process of claim 3 in which the fibrous cellulosic material is selected from the group consisting of cotton and paper.

5. The process of claim 3 in which the fibrous proteinaceous material is selected from the group consisting of wool, leather and fur. 

1. A PROCESS FOR WATERPROOFING FIBROUS CELLULOSIC AND FIBROUS PROTEINACEOUS MATERIALS COMPRISING IMMERSING THE MATERIAL TO BE WATERPROOFED IN A SOLUTION OF AN A-PYRONE OF THE FORMULA
 2. The process of claim 1 in which the Alpha -pyrone is
 3. The process of claim 2 in which the solution contains about 5.0 to 6.0% of Alpha -pyrone on a weight per volume basis.
 4. The process of claim 3 in which the fibrous cellulosic material is selected from the group consisting of cotton and paper.
 5. The process of claim 3 in which the fibrous proteinaceous material is selected from the group consisting of wool, leather and fur. 